[The potentially infected newborn infant].

In order to establish relationship between premature rupture of membranes (RPM) and neonatal infection, together with the importance of other factors during this process, 50 newborns with history of RPM were studied. In a control group and in groups of newborns with less than and more than 24 hours of plain RPM, related to clinically healthy and vigorous infants, no case of infection was found. On the other hand, 30% and 60% respectively of infections were found in groups less than and more than 24 hours of RPM, but with the presence of other contaminating factors that impair immunological response of the newborn, such as: acute maternal infection, prolonged delivery, unexpected birth, pediatric reanimation procedures, organic immaturity, fetal suffering, immediatie neonatal depression and intercurrent pathology. There were two deaths: a case with RPM of 5 hours and another one with 38 hours, but both with high rating due to the presence and intensity of "aggravating factors" mentioned having internal action mechanism that apparently of restrains to the perpetuation of the hypoxia-acidosis cycle. A provisional sheet is presented to evaluate such "aggravating factors" considering that an RPM associated to them represents a high risk of neonatal infection. In cases of clinically healthy newborns with plain RPM, we advice only to watch over them for 3--5 day, but no antimicrobial treatment at all.